1. Field of the Invention
This invention relates to the capture, storage and recirculation of heat energy in residential and commercial buildings. The present invention is intended to be incorporated into new construction, although the present invention may be utilized in pre-existing buildings as well. In general, the present invention provides means to capture, store, and recirculate heat generated within a structure, and more specifically provides for the storage of heat energy that is generated or collected at or near the highest point of a structure. Heated air is generated at the roof of a building due to natural processes and/or design features incorporated into a building's structure. The heated air is redirected into a storage facility beneath a structure, and the storage facility utilizes the heated air to warm a body of water that is then utilized for both potable water heating and heating of the building. In addition, the heated air output from the storage facility is utilized to supplement the building's heating system.
Heated air within a building rises; a natural result of this convective flow causes heated air to collect at or near the underside of the peak of the structure. Adding to the temperature rise under the roof structure is the effect of sunlight on a roof. In particular, sunlight on the surface of a roof, and in particular on roof shingles, causes an increase in the temperature of the air underneath the roof surface. This accumulation of additional heat, in addition to being of waste of available energy, causes degradation of the structure of a roof and increases the rate of deterioration of roof shingles. In current designs, much if not all of that heat generated either remains unutilized in the attic or top space of the interior of the building, or is lost to the environment.
While collecting and recirculating heated air that either accumulates or is generated on or under the roof of a structure is desirable to cool the roof structure, such a system loses heat that could be stored for later use. The heat energy generated during the day may be stored for use after dark when the ambient temperature both inside and outside of a structure decreases. The stored heat may be used to maintain a comfortable temperature inside of a structure.
Present designs for cooling roof structures waste significant heat energy that may be recaptured, stored, and utilized within the structure itself, reducing overall heat loss within the structure. Further, although previous designs have provided means for the capture of heat energy from the sun on the roofs of buildings, those previous designs rely upon complicated fluid circulation systems that are costly, inefficient, and difficult to maintain. And, failures of such systems can be catastrophic; water ruptures and leakage can result in significant structural damage.
What is needed is a method of enhancing the cooling of a roof structure while providing the option of simultaneously supplementing a building's heating system. What is further needed is a method of capturing and storing, for later use, heat energy that is either created or collected at the peak of a structure. Such a system should utilize solar energy to generate heating for the building, carry heat away from the roof to reduce structural heating and shingle degradation, supplement the existing heating system of the building, and provide means to store heat energy for later use and convert the heat energy so that it may be utilized in a building's other systems requiring a heat source.
It therefore an object of the present invention to generate heat energy from solar energy at the roof of a structure. It is a further object of the present invention to provide means to carry heat away from the roof of a structure, and divert the heat for recirculation within a structure to either supplement or replace the need for common heat sources such as furnaces, electrical heat devices, heat pumps, and the like. It is yet a further object of the present invention to convert collected heat energy for storage and heating of a building's heated water supplies. The present invention comprises an air capture and circulation system wherein a roof cap structure, vent, heated air collecting panels, and circulation devices are used in combination to prevent heated air rising from the eaves to the ridge during winter months from escaping into the atmosphere, and to channel that heated air from the ridge area to a storage means for later use.
2. Description of the Prior Art
Various methods have been used to store heat for later use within a structure. For example, U.S. Pat. No. 5,038,850 to Choi is for a “Cooling and Heat Accumulating Type Electrical Cooling and Heating System and Method for Implementing the Same.” The Choi invention teaches a heat and cooling accumulation chamber. However, the Choi invention utilizes electric power for the heat generation in the device. Further, the Choi invention relies upon forced flow of air to provide heating or cooling flow out of the heat and cooling accumulation chamber.
U.S. Pat. No. 4,285,332 issued Aug. 25, 1981 to McHugh teaches a “Building Having Solar Heating System.” The McHugh invention provides for the capture of solar heat through a circulation system. The invention of McHugh, however, requires the flow of water through the structure, which requires that the water to be circulated and heated is built into the structure itself. The McHugh invention further requires (as does most solar heat prior art) a water or other liquid being circulated within a closed system to capture and store the solar heat.
U.S. Pat. No. 4,000,851 issued Jan. 4, 1977 to Heilemann teaches a “Solar-Heated Dwelling.” That invention, as with the McHugh patent, teaches water flow for the capture of solar heat energy. The Heilemann invention further teaches a heat reservoir beneath the structure. However, the Heilemann, as with the McHugh invention, relies upon water flow to carry heat from the rooftop solar panels. In addition, the heat reservoir relies upon a set of rocks to store heat from the solar panels. This system is inherently inefficient in that the heat to be stored must be gathered by water at the roof, where the pipes carrying the liquid must be heated, and thence the water within the pipes. This heated water must then be circulated down to the bottom of the structure, where the heat to be stored must be passed out of the water, through the pipe walks, through the ambient air within the reservoir, and then into the rocks. The Heilemann invention then relies upon the rocks to heat the floor slab of the structure, which in turn theoretically provides heat to the overlying room. The Heilemann system is not only inefficient to the extent that it requires a structurally and mechanically complicated system, but it is further undesirable in that the circulation of water in the system poses a significant threat of structural damage and costly repairs should part of the system fail. In addition, the multiple processes required for the transfer of heat to the structure are sources of significant inefficiencies.
Similarly, U.S. Pat. No. 4,000,850, issued Jan. 4, 1977 to Diggs for “Solar Heated and Cooled Modular Building” teaches a system for the capture and storage of heat collected at the roof of a structure. As with the Heilemann invention, however, the Diggs invention requires a water circulation system to collect and transport heat energy from the roof of a structure. In addition, these preexisting systems do little to reduce the temperature of the liquid being circulated prior to the liquid being returned to the rooftop heat source. Because the heat transfer into and out of the circulating liquid is limited, the capacity to capture more heat by the water is limited, thereby reducing the efficiency of the system.
U.S. Pat. No. 4,484,566, issued Nov. 27, 1984 to Gonzalez for “Solar Collector Panel and Heat Storage System” teaches a system designed to capture and store heat from the sun. In particular, the Gonzalez invention teaches a solar heating system that relies upon solar panels and a water tank storage system. The solar panels taught by Gonzalez incorporate circuitous air flow passages intended to increase the residence time of air within the solar panels. The Gonzalez invention further teaches the water tank storage of heat energy generated within the taught solar panels. The water storage tank, in turn, provides heated air to the structure located above the water-storage tank. However, the Gonzalez system provides at best an inefficient means to remove unwanted heat from the system or the structure itself; having a heat removal process is critical for efficient building climate control. In addition, the Gonzalez design requires the reversal of ambient flow within the structure of the solar panels that are intrinsic to the Gonzalez design. Without forced air flow to counteract the natural rise of heated air, heated air within the Gonzalez solar panels will collect and become trapped inside the solar panel structure. As an additional limitation, the Gonzalez-invention teaches a closed system wherein there is no opportunity to refresh the air within the system with air replenished from outside of a structure. There is also no means of utilizing natural air flow mechanisms to capture, store, and vent heated air. And even though the Gonzalez invention teaches a water tank as means to trap and store collected heat energy, the invention is limited in that the water tank only utilizes the heat energy collected within the water tank to provide heat energy to the ambient air moving up and into a structure, and makes no other use of the heat energy trapped within the water stored within the tank. Finally, the Gonzalez invention is inherently inefficient in that it only provides limited control in response to seasonal variations in ambient temperature.
None of these previous inventions provide means for enhancing the heat collection at the roof of a structure. Nor do they provide an efficient means for the collection and storage of the heat energy collected. The Heilemann, Diggs, and Gonzalez inventions, the heat storage means does not provide efficient means for removing the heat energy from the circulated heat collecting medium. Nor do any of the systems make full utilization of heat trapped in storage means, such as a water storage tank, where such heated water may be utilized for heat and hot water supply.
What is needed, therefore, is an efficient method of storing heat to be utilized within a structure. More particularly, an efficient method of capturing, recirculating and storing heat generated at or on the roof of structure is needed where the heat is transferred directly from the collection medium into the storage medium. Such a system should also preferentially provide as simplified a system as possible so as to reduce heat losses as well as mechanical failures.
The current invention is an improvement over the prior art in that it provides a new means by which heated air that accumulates in the roof structure of buildings is captured within a roof cap structure, stored, and then circulated into the primary heating cycle of a building structure during winter months, thereby increasing the efficiency of the heat system. The present invention assists and enhances the passive air flow that results from building designs.
It is an object of the present invention to provide a heat generation, storage and recirculation system that utilizes heat collecting panels to be used during winter months to increase the amount of heated air available to direct into the primary heating system of the building structure. As an added benefit, during the summer months the current invention permits the discharge of heated air that rises to the crown from the roof area to the outside. The current invention does not require a particular building design and conveniently may be secured atop an existing roof cap, utilized to replace an existing roof cap altogether, or used in new construction. The storage portion of the present invention may be installed during construction of a building, or may be installed to an existing structure.
It is a further object of the present invention to provide a means to supplement the heating system of a structure through the generation and capture of air at the surface of a roof heated by solar energy.
It is a further object of the present invention to provide a heat generation, recirculation, and storage system that directs heated air away from the roof of a structure.
It is a further object of the present invention to store and convert heat energy to be utilized by a building's heated water systems.